1 files changed, 12 insertions, 20 deletions

diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 1276cab85e3e..ea68a478fad6 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -569,8 +569,10 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
            does sequence test, SYN is truncated, and thus we consider
            it a bare ACK.
 
-           Both ends (listening sockets) accept the new incoming
-           connection and try to talk to each other. 8-)
+           If icsk->icsk_accept_queue.rskq_defer_accept, we silently drop this
+           bare ACK.  Otherwise, we create an established connection.  Both
+           ends (listening sockets) accept the new incoming connection and try
+           to talk to each other. 8-)
 
            Note: This case is both harmless, and rare.  Possibility is about the
            same as us discovering intelligent life on another plant tomorrow.
@@ -638,6 +640,13 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
                 if (!(flg & TCP_FLAG_ACK))
                         return NULL;
 
+                /* If TCP_DEFER_ACCEPT is set, drop bare ACK. */
+                if (inet_csk(sk)->icsk_accept_queue.rskq_defer_accept &&
+                    TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) {
+                        inet_rsk(req)->acked = 1;
+                        return NULL;
+                }
+
                 /* OK, ACK is valid, create big socket and
                  * feed this segment to it. It will repeat all
                  * the tests. THIS SEGMENT MUST MOVE SOCKET TO
@@ -676,24 +685,7 @@ struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
                 inet_csk_reqsk_queue_unlink(sk, req, prev);
                 inet_csk_reqsk_queue_removed(sk, req);
 
-                if (inet_csk(sk)->icsk_accept_queue.rskq_defer_accept &&
-                    TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) {
-
-                        /* the accept queue handling is done is est recv slow
-                         * path so lets make sure to start there
-                         */
-                        tcp_sk(child)->pred_flags = 0;
-                        sock_hold(sk);
-                        sock_hold(child);
-                        tcp_sk(child)->defer_tcp_accept.listen_sk = sk;
-                        tcp_sk(child)->defer_tcp_accept.request = req;
-
-                        inet_csk_reset_keepalive_timer(child,
-                                                       inet_csk(sk)->icsk_accept_queue.rskq_defer_accept * HZ);
-                } else {
-                        inet_csk_reqsk_queue_add(sk, req, child);
-                }
-
+                inet_csk_reqsk_queue_add(sk, req, child);
                 return child;
 
         listen_overflow: